3,440 research outputs found
CIN classification and prediction using machine learning methods
The aim of this paper is a comparison of the existing classification algorithms with different parameters, and selection those ones, which allows solving the problem of primary diagnosis of cervical intraepithelial neoplasia (CIN), as it characterizes the condition of the body in the precancerous stage. The paper describes a feature selection process, as well as selection of the best models for a multiclass classification. © 2017 Author(s)
Role of direct exchange and Dzyaloshinskii-Moriya interactions in magnetic properties of graphene derivatives: CF and CH
According to the Lieb's theorem the ferromagnetic interaction in
graphene-based materials with bipartite lattice is a result of disbalance
between the number of sites available for electrons in different
sublattices. Here, we report on another mechanism of the ferromagnetism in
functionalized graphene that is the direct exchange interaction between spin
orbitals. By the example of the single-side semihydrogenated (CH) and
semifluorinated (CF) graphene we show that such a coupling can partially or
even fully compensate antiferromagnetic character of indirect exchange
interactions reported earlier [Phys. Rev. B {\bf 88}, 081405(R) (2013)]. As a
result, CH is found to be a two-dimensional material with the isotropic
ferromagnetic interaction and negligibly small magnetic anisotropy, which
prevents the formation of the long-range magnetic order at finite temperature
in accordance with the Mermin-Wagner theorem. This gives a rare example of a
system where direct exchange interactions play a crucial role in determining a
magnetic structure. In turn, CF is found to be at the threshold of the
antiferromagnetic-ferromagnetic instability, which in combination with the
Dzyaloshinskii-Moriya interaction can lead to a skyrmion state.Comment: 10 page
Electric field gradients in s-, p- and d-metal diborides and the effect of pressure on the band structure and T in MgB
Results of FLMTO-GGA (full-potential linear muffin-tin orbital -- generalized
gradient approximation) calculations of the band structure and boron electric
field gradients (EFG) for the new medium-T superconductor (MTSC), MgB,
and related diborides MB, M=Be, Al, Sc, Ti, V, Cr, Mo and Ta are reported.
The boron EFG variations are found to be related to specific features of their
band structure and particularly to the M-B hybridization. The strong charge
anisotropy at the B site in MgB is completely defined by the valence
electrons - a property which sets MgB apart from other diborides. The boron
EFG in MgB is weakly dependent of applied pressure: the B p electron
anisotropy increases with pressure, but it is partly compensated by the
increase of core charge assymetry. The concentration of holes in bonding
bands is found to decrease slightly from 0.067 to 0.062 holes/B under
a pressure of 10 GPa. Despite a small decrease of N(E), the Hopfield
parameter increases with pressure and we believe that the main reason for the
reduction under pressure of the superconducting transition temperature, T,
is the strong pressure dependence of phonon frequencies, which is sufficient to
compensate the electronic effects.Comment: 12 pages, 3 figure
Role of Coulomb correlation on magnetic and transport properties of doped manganites: La0.5Sr0.5MnO3 and LaSr2Mn2O7
Results of LSDA and LSDA+U calculations of the electronic structure and
magnetic configurations of the 50% hole-doped pseudocubic perovskite
La0.5Sr0.5MnO3 and double layered LaSr2Mn2O7 are presented. We demonstrate that
the on-site Coulomb correlation (U) of Mn d electrons has a very different
influence on the (i) band formations, (ii) magnetic ground states, (iii)
interlayer exchange interactions, and (iv) anisotropy of the electrical
transport in these two manganites. A possible reason why the LSDA failures in
predicting observed magnetic and transport properties of the double layered
compound - in contrast to the doped perovskite manganite - is considered on the
basis of a p-d hybridization analysis.Comment: 11 pages, 3 figure
Design of professional career by future experts in the sphere of art and culture
The problem of planning of professional life is discussed by experts in the field of art and culture, experience of application of active forms of education with use of presentation during psychology and pedagogical lessons is described in the article, aspects of efficiency of their realization in training of students of higher education institution are considered, possibilities of application of modern means of presentation in the course of professional formation of future specialist producer are revealed. Problems of design of a professional way of a personality in the context of modern social and economic conditions are complicated by unstable conditions, characterized by social, economic and political changes, prompt transformations in the sphere of values and purposes of personality that predetermines essentially new requirements to psychological structure of the personality which would provide the most effective self-realization and success in professional activity. That means that actual tendencies of process of vocational training of future experts in the sphere of art are ways of application of means of modern technologies in the course of training. We believe that use of active forms of education with use of presentation, and also analysis of perceived phenomena by students will form readiness of future experts of the sphere of art and culture for design of own professional future.peer-reviewe
Preface of “the third symposium on mathematical methods in economics and nature use”
[краткое описание не найдено
Softening and hardening of ECAP nickel under ultrasonic treatment
Commercially pure nickel was processed by equal channel angular pressing (ECAP) through
route Bc for 12 passes to obtain an ultrafine grained (UFG) microstructure and further subjected
to an ultrasonic treatment (UST) which introduced a maximum amplitude equivalent to anormal
stresses of 100 MPa in a steady state regime. It was observed that the microstructure of UFG Ni
can be differently altered depending on the position in the sample, i.e. on the amplitude of the
ultrasonic wave. The microstructural analysis demonstrated a lower dislocation density (due to
the activation of recovery) at the cross section of the specimen subjected to UST at an amplitude
equal to 0.8 of the maximum one, plus enhanced hardening in the cross section at the maximum
amplitude.Preprin
МЕТОДЫ И ПРОЦЕДУРЫ КОМПЛЕКСНОЙ ДИАГНОСТИКИ РИСКОВ ПРЕДПРИЯТИЙ РЕАЛЬНОГО СЕКТОРА ЭКОНОМИКИ
The article covers a conceptually new method of industrial Company Risks’ complex Diagnosis. This method orders the possibility of diagnosing these risks as events resulting from each of the factors and leading to the changes of the company and company’s systems/subdivisions activities’ results.В статье представлен принципиально новый метод проведения процедуры комплексной диагностики внутренних рисков предприятий реального сектора экономики. В рамках данного метода предлагается диагностировать внутренние риски предприятий как события, которые генерируются базовыми элементами систем/подразделений и могут, в случае свершения, привести к изменению результатов деятельности этих систем/подразделений, а также результатов деятельности предприятия в целом
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